Skip to content
Fencer Intel
medium 4.4

CVE-2011-3607 json

Integer overflow in the ap_pregsub function in server/util.c in the Apache HTTP Server 2.0.x through 2.0.64 and 2.2.x through 2.2.21, when…

published 2011-11-08 15 y ago modified 2026-06-16 4 mo ago also EUVD-2011-3566

cvss
4.4
version 2.0, NVD
cisa kev
Not listed
not in CISA's catalog
epss
4.9%
EPSS 4.9% chance of exploitation in 30 days, percentile 92%
public exploits
1
Exploit-DB

Summary

Integer overflow in the ap_pregsub function in server/util.c in the Apache HTTP Server 2.0.x through 2.0.64 and 2.2.x through 2.2.21, when the mod_setenvif module is enabled, allows local users to gain privileges via a .htaccess file with a crafted SetEnvIf directive, in conjunction with a crafted HTTP request header, leading to a heap-based buffer overflow.

Patch / fix

  • apache2 Debian 14, Debian 13, Debian 12 2.2.21-4

debian advisories DEBIAN-CVE-2011-3607

  • httpd RHEL 5 2.2.3-63.el5_8.1
  • mod_ssl RHEL 5 1:2.2.3-63.el5_8.1
  • httpd-manual RHEL 5 2.2.3-63.el5_8.1
  • httpd RHEL 6 2.2.15-15.el6_2.1
  • mod_ssl RHEL 6 1:2.2.15-15.el6_2.1
  • httpd-tools RHEL 6 2.2.15-15.el6_2.1
  • httpd-manual RHEL 6 2.2.15-15.el6_2.1
  • httpd jboss enterprise web server 1 2.2.17-15.4.ep5.el5

red hat advisories RHSA-2012:0323RHSA-2012:0128RHSA-2012:0542

  • apache2 openSUSE Tumbleweed 2.4.23-4.1

opensuse advisories openSUSE-SU-2024:10268-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2011-3607 updated cvss 4.4

httpd: ap_pregsub Integer overflow to buffer overflow

  • Red Hat Directory Server 8 httpd Red Hat Enterprise Linux 4 httpd
    affected: no fix planned “Will not fix”
  • Red Hat Enterprise Linux (v. 5 server) httpd 2.2.3-63.el5_8.1, mod_ssl 2.2.3-63.el5_8.1, httpd-manual 2.2.3-63.el5_8.1 Red Hat Enterprise Linux Desktop (v. 5 client) httpd 2.2.3-63.el5_8.1, mod_ssl 2.2.3-63.el5_8.1
    fixed: vendor fix RHSA-2012:0323
  • Red Hat Enterprise Linux Desktop (v. 6) httpd 2.2.15-15.el6_2.1, httpd-tools 2.2.15-15.el6_2.1 Red Hat Enterprise Linux Desktop Optional (v. 6) httpd 2.2.15-15.el6_2.1, mod_ssl 2.2.15-15.el6_2.1, httpd-manual 2.2.15-15.el6_2.1 Red Hat Enterprise Linux HPC Node (v. 6) httpd 2.2.15-15.el6_2.1, httpd-tools 2.2.15-15.el6_2.1 Red Hat Enterprise Linux HPC Node Optional (v. 6) httpd 2.2.15-15.el6_2.1, mod_ssl 2.2.15-15.el6_2.1, httpd-manual 2.2.15-15.el6_2.1 Red Hat Enterprise Linux Server (v. 6) httpd 2.2.15-15.el6_2.1, mod_ssl 2.2.15-15.el6_2.1, httpd-tools 2.2.15-15.el6_2.1, httpd-manual 2.2.15-15.el6_2.1 Red Hat Enterprise Linux Workstation (v. 6) httpd 2.2.15-15.el6_2.1, mod_ssl 2.2.15-15.el6_2.1, httpd-tools 2.2.15-15.el6_2.1, httpd-manual 2.2.15-15.el6_2.1
    fixed: vendor fix RHSA-2012:0128
  • Red Hat JBoss Enterprise Web Server 1 for RHEL 5 Server httpd 2.2.17-15.4.ep5.el5, mod_ssl 2.2.17-15.4.ep5.el5, httpd-manual 2.2.17-15.4.ep5.el5 Red Hat JBoss Enterprise Web Server 1 for RHEL 6 Server httpd 2.2.17-15.4.ep5.el6, mod_ssl 2.2.17-15.4.ep5.el6, httpd-tools 2.2.17-15.4.ep5.el6, httpd-manual 2.2.17-15.4.ep5.el6
    fixed: vendor fix RHSA-2012:0542
  • Red Hat JBoss Web Server 1.0
    fixed: vendor fix RHSA-2012:0543
  • Red Hat RHEL Desktop Workstation (v. 5 client) httpd 2.2.3-63.el5_8.1, httpd-manual 2.2.3-63.el5_8.1
    fixed: vendor fix RHSA-2012:0323

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Timeline

  1. First public exploit (EDB-41769)
  2. Published

Exploit prediction

4.90% chance of exploitation in the next 30 days, higher than 92% of all scored CVEs (FIRST EPSS, 2026-11-09).

Exploits and checks

  • EDB-41769 Apache < 2.0.64 / < 2.2.21 mod_setenvif - Integer Overflow dos, 2011-11-02
  • bugs.launchpad.net https://bugs.launchpad.net/ubuntu/+source/apache2/+bug/811422 referenced PoC, tagged "exploit" by a source, unverified
  • halfdog.net http://www.halfdog.net/Security/2011/ApacheModSetEnvIfIntegerOverflow/DemoExploit.html referenced PoC, tagged "exploit" by a source, unverified
  • halfdog.net http://www.halfdog.net/Security/2011/ApacheModSetEnvIfIntegerOverflow/ referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 2.0 4.4 AV:L/AC:M/Au:N/C:P/I:P/A:P

Classification

Weakness
Technology feeds

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.